In the presently favored picture of star formation, mass is transferred from disk to star via magnetospheric accretion and out of the system via magnetically driven outflows. This magnetically mediated mass flux is a fundamental process upon which the evolution of the star, disk, and forming planetary system depends. Our current understanding of these processes is heavily rooted in young solar analogs, T Tauri Stars (TTS). We have come to understand recently, however, that the higher mass pre-main sequence (PMS) Herbig AeBe (HAeBe) stars have dramatically weaker dipolar fields than their lower mass counterparts. We present our current observational and theoretical efforts to characterize magnetospherically mediated mass transfer within HAeBe star+disk systems. We have gathered a rich spectroscopic and interferometric data set for several dozen HAeBe stars in order to measure accretion and mass loss rates, assess wind and magnetospheric accretion properties, and determine how spectral lines and interferometric visibilities are diagnostic of these processes. For some targets, we have observed spectral line variability and will discuss ongoing time-series spectroscopic efforts.

The ratios of hydrogen Balmer emission line intensities in cataclysmic variables are signatures of the physical processes that produce them. To quantify those signatures relative to classifications of cataclysmic variable types, we applied the multivariate statistical analysis methods of principal components analysis and discriminant function analysis to the spectroscopic emission data set of Williams (1983). The two analysis methods reveal two different sources of variation in the ratios of the emission lines. The source of variation seen in the principal components analysis was shown to be correlated with the binary orbital period. The source of variation seen in the discriminant function analysis was shown to be correlated with the equivalent width of the Hβ line. Comparison of the data scatterplot with scatterplots of theoretical models shows that Balmer line emission from T CrB systems is consistent with the photoionization of a surrounding nebula. Otherwise, models that we considered do not reproduce the wide range of Balmer decrements, including ‘inverted’ decrements, seen in the data.

An anti-correlation between the optical brightness and the strength of the Hα emission was observed from two Be/X-ray binaries, A0535+26 and MXB 0656-072: when the optical brightness showed a decrease, the intensity of the Hα emission displayed an obvious increase. This anti-correlation is interpreted as the result of the mass ejection from the Be star. After the mass ejection event, a cavity or low-density region will be developing in the inner parter of the circumstellar disk. The X-ray outbursts of the Be/X-ray binaries might be connected with the mass ejections from the Be star.

We summarize recent efforts from our group to constrain the nature of both stars in the Eta Carinae binary system and its orbital parameters by studying the influence of the companion star on the spectrum of the primary star. We find that the cavity in the dense wind of the primary star strongly affects multi-wavelength diagnostics such as the ultraviolet spectrum, the optical hydrogen lines, and the shape of the near-infrared continuum region. These diagnostics have been previously interpreted as requiring a latitude-dependent wind generated by a fast-rotating primary star, but the effects of the companion on them provide tenuous evidence that the primary star is a rapid rotator.